Seminar im Wildenhof, Rursee Eifel

Sensor-based identification of spent
refractory bricks
Henning Knapp
Unit of Mineral Processing, RWTH Aachen University
L. Horckmans, F. Bouillot, C. Fricke-Begemann, J. Makowe, A. Ducastel, A. Stark
This project has received funding from the European Union’s Seventh Programme
for research, technological development and demonstration under grant agreement
No 603809.
Refractories
 All high-temperature processes consume
refractories
– Steel
10 kg/t
– Glass
4 kg/t
– Cement
1 kg/t
– Waste incineration 5.5 kg/t
 5.5 Mt of refractories produced in
Europe per year (Value: 3.6 billion €)
source: PRE 2009
 More than 600 €/t
June 17, 2015
Balkan Mineral Processing Congress, Belgrade, Serbia
Henning Knapp
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Types of refractories
 A great variety of
refractory types
 Strict quality
specifications for raw
materials
 Geographic
concentration of
some raw materials
June 17, 2015
Raw material
Formula
Melting point
Main source
Silica
SiO2
1720° C
Global
Fireclay
SiO2 + Al2O3
1100° C
Global
Alumina silicate
SiO2 + Al2O3
1350° C
China
Alumina
Al2O3
2050° C
Synthetic
Zirconia
ZrO2
2715° C
South Africa
Zircon
ZrSiO4
1775° C
Australia
Chromite
FeCr2O4
2265° C
South Africa
Spinel
MgAl2O4
2135° C
Synthetic
Magnesia
MgO
2820° C
China
Sinter dolomite
CaO + MgO
2370° C
Europe/ Global
Graphite
C
3600° C
China
Balkan Mineral Processing Congress, Belgrade, Serbia
Henning Knapp
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Aim of the REFRASORT project
 Close the raw materials
cycle
 Avoid production of waste
 Increase resource
utilization
June 17, 2015
Balkan Mineral Processing Congress, Belgrade, Serbia
Henning Knapp
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Sensor-based sorting
 Single particle
separation
Detection
 Quick and
reproducible
measurements
 High throughput
compared to
handpicking
Feed Preparation
Material
Presentation
Rejected Fraction
June 17, 2015
Data Processing
Separation
Accepted Fraction
Balkan Mineral Processing Congress, Belgrade, Serbia
Henning Knapp
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Laser Induced Breakdown Spectroscopy (LIBS)
 A laser beam is focused
on the samples surface
 Plasma created

The plasma light is
collected and analyzed
 Elemental composition
can be calculated from
spectra
L1: diverging lens; L2 two lens focusing system, DM
dichroitic mirror, SM1,2 scanner mirrors, S sample, MV
measuring volume, L3 focusing lens, FO optical fiber, PD
photodiode.(Werheit et al., 2011)
June 17, 2015
Balkan Mineral Processing Congress, Belgrade, Serbia
Henning Knapp
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Test setup
 Cylinders of eight refractory types tested with LIBS
 The cylinders represent three main types of bricks, further subdivided in
two or three types respectively
 The cylinders were measured on a moving belt
June 17, 2015
Balkan Mineral Processing Congress, Belgrade, Serbia
Henning Knapp
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LIBS measurements
 Each measurement takes less than 100 ms
 Each cylinder was measured on several different
spots
 Mean values of three elements were used to
identify the different brick types
June 17, 2015
Balkan Mineral Processing Congress, Belgrade, Serbia
Henning Knapp
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LIBS tests
MgO
June 17, 2015
Doloma
Al-Si
Balkan Mineral Processing Congress, Belgrade, Serbia
Henning Knapp
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Conclusion
 Refractory bricks hold a huge potential to create value
 Almost no recycling into high-value applications by now
 The LIBS-system is able to identify the main brick types
 Combining the LIBS-system with
suitable mechanical technologies
can enable recycling
June 17, 2015
Balkan Mineral Processing Congress, Belgrade, Serbia
Henning Knapp
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Thank you for your attention!
Are there any questions?
The REFRASORT project has received funding from the European Union’s Seventh Program for research,
technological development and demonstration under grant agreement No 603809.
June 17, 2015
Balkan Mineral Processing Congress, Belgrade, Serbia
Henning Knapp
12